Tensions between Russia and Ukraine have flared in recent weeks after years of strain began in 2014 when street protests in Kyiv resulted in the flight of the pro-Moscow president and annexation of Crimea by Russian forces.
The data also showed that the Serena M tanker shipped 30,000 tonnes of diesel to the port of Yuzhny from Turkey in the second half of March.
The operation, which saw customs officers from the port city of Ningbo join forces with local law enforcement and maritime police, spanned eight Chinese regions, including the coastal provinces of Zhejiang, Jiangsu, Shandong and Fujian.
Customs authorities described the swoop as "one of the most extensive operations" to combat refined oil smuggling along China's southeast coast in recent years, in terms of area.
The deal calls for up to 10 million tonnes of oil products shipments, split over three years, from March, and is part of a show of support for Minsk from Moscow following last year's presidential election.
Latvian ports of Riga and Ventspils are projected to get up to 111,000 tonnes of gasoline produced at the Mozyr refinery, an increase from 74,000 tonnes set for February.